Overlock
An Overlock-Sewing Machine sews and hems seams and cuts off the leftover cloth. They have no bobbins, using instead 3 or 4 thread cones. Some overlock machines can be set up to do a rolled or blind hem, but all can bind off the edge with an overcast stitch.
A "Serger" is an Overlock machine that uses 5 thread cones, and will simultaneously bind the edge with an overcast stitch, and run a chainstitch at a 1/2" seam allowance.
A Coverlock can do hems in the middle of a cloth by having the (detachable) knife removed.
For other sewing-machine stitches see: Lockstitch.